Field assistant Ben Gready measures the electrical conductivity of the ‘N’ glacier outflow. By making this measurement at different times of the season, scientists can compare concentrations of dissolved nutrients in meltwater passing through the subglacial environment. Early in the melt season, the network of tunnels and chasms under the glacier is less efficient at draining meltwater, extending the meltwater's contact with sediments and bedrock, thus picking up more dissolved nutrients.